Chain repair link



Dec. 16, 19 52 M. R. DOCK 2,621,471

CHAIN REPAIR LINK Filed March 27, 1951 2 SHEETS-SHEET 1 3 az/z, ATTORNEYS.

Dec; 16, 1952 M. R. DOCK 2,621,471

I CHAIN REPAIR LINK Filed March 27. 1951 2 Sl-lEETS--Sl-IEET 2 A TTORNEYS.

Patented Dec. 16, 1952 UNITE a state i AT B NT F I The present invention relates to, chain, shackles and, more particularly, to. those of the stud link type, constituting, an improvement of thesubj ect matter of my prior United States Patent No..

lar; skill or familiarity with the construction, and, the latter, is thus especially useful under trying conditionsin. fields ofjcombat-and thelike': The parts ,of the preferred"embodiment-are so designed as, to assure, maximum'strengthwith minimumlikelihood} in use of] accidental disengagement of parts and: damage: thereto which-might otherwise resist or prevent desired? intentional disengage mentjfor replacementoffwnrn parts:

A: more specific, 0biect..offthe present invention is toprovidesucha chain shackle structure in which alLof; the sections have maleand' female threads atioppositeendsof'such hand as: to make side link sections, interchangeably mateablewith end'li'nk sections and'which ,obviously'at aglance are. to, be arranged for assembly in symmetrical order withallj of the mouthsoftheiemale sockets opening in one direction and all of the male members; extending. in the opposite direction; toward thel'latter entirely aroundthelink,

Another object of. the present inventionlis to equip at least some :of: such side linksections with stud i lugsautomatically, alignable. for connection whenthe threaded engagements of said'end'link sections with said side. link sections areidrawnv upto intended substantial tightness.

Aiurther object of the-inventionistoprovide uniquesand-simple means for-connecting the, stud lugs together to, form. a rigid stud structurethe.

parts of which may be lockedtogether. efiectively, to-prevent accidental loosening thereof Whileprotecting them in use to-permit intentional disengagement.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements and; arrangement of parts, whichlwillthe exemplified inthe construction hereinafter setrfcrth, and

the scopeofthe invention will be indicated in the claims.

7 Claims: (Cl. 5985) For. a fuller understanding. of the nature and objects of the invention, reference shoulibeihad. to the following; detailed description taken in;

connection with the accompanying drawings, in which:;

Fig; 1* is-a top plan view of an embodiment ofthe stud link chain'shackle'of the present:invention with the partsthereof shown. in assembled positions;

Fig. .21is an explodedvi'ew'of the structure shown. in Fig, 1: and with partsin section and in unassembled positionsshowing relative position of, parts-as'laid out for assembly;

Fig, 3 isa top plan-View ofthestructure. shown in Figs. 1; and Z'indicating relative position of parts as theyare being assembled in a particular manner;-

Fig. 4 isa sectional view, to anvenlargedscale; taken substantially on line 44 of Fig; 1", but showing certain stud lug' connecting means in initial positions prior to connecting engagement thereof;

Fig! 5 is a perspective'viewto an enlargedscale, withparts' broken away; oi interengageable male and female members constituting one of,the:four." pairs thereoffeaturing-the structureof Figs; 1 to 4, inclusive but arrangedobliquelywithrespectto each other before the necessary: alignment for interengagement so ,asybest to illustrate structural features'thereof;

Fig. 6 is an enlarged elevationalend view of the femalemember'shown inFfig, 5; illustrating a certain thread remova-l feature-thereof. V

Fig.- 7 is avieW-similar toFig. 6 of the endi' of' themale member of Fig. 5'; V

Fig; 8 is afragmentary view; with partsjrr sec;- tion; of a slightly-modified-formof interengagingi male-and female members which may beemployed-- in the linkstructureof Figs: 1 to,7,l inclusive;;and"

Fig. 9 is a diagrammatic, exploded view of the parts of a modified-formof link structureofthe present invention as laid out preliminaryto-assembly thereof and to illustrate the possibleuse of additional side link elements which readily may beadcled tothe basic parts-of the structure-shown in Figs; 1 to 3, inclusive; Y

Referring" to the drawings; in. which like nue merals identify similarparts throughout; it will be seen that'a preferred-embodiment of'the pres= ent' invention may" comprise a pair of opposed semi-elliptical end sections In; It) and a pair of? interposed: side" sections Iii. H; with. the, latter preferably tied together across; the link by a transverse stud structure; ili Thev structional detailsofthe. various partsof: that embodimentof the stud link chain shackle of the present invention are best seen in Fig. 2.

As shown in Fig. 2, each semi-elliptical end section III preferably is formed of round stock and comprises a main portion I3 provided on one end with a male member I4 and in the other end with a female socket I5, with the axes of the male member and female socket being arranged substantially parallel to each other. The male member I4 is suitably provided with a helical or spiralled thread I5 of any desired form, either right-handed or left-handed, and the female socket I5 is provided with an internal helical or spiralled thread I'I. Although V-shaped threads may be used, the square threads shown are preferred for purposes of strength, and although single entry threads are indicated, plural entry threads may be employed if it is desired to speed assembly operations. With respect to the selected hand for the male and female threads of an end section II], those threads are opposite in hand. For example, if the male thread I6 is left-handed as shown, the female thread I! is right-handed. The spindle, shank or core I8 of male member I4 may be tapered, but preferably is substantially cylindrical for a major portion of its length but with the threads being run out at the male member base I9 to increase the diameter thereof for purposes of strength. The base I9 of male member core I8 connects with the major portion I3 at a stop shoulder or abutment 20. The female socket I5 is made complementary in shape to a male member like male member I4 except that the threads thereof are opposite in hand, with its mouth 2| flared for fit to the tapered base I9 of such male member. End edge 22 of the end section major portion I3 circumambient of the mouth 2I of female socket I5 also forms a stop shoulder or abutment, as will be more fully explained hereinafter.

Each side section II comprises a major portion 23 of cylindrical stock preferably of a diameter substantially that of the major portion I3 of each end section I0. One end of the major portion 23 of side section II is provided with an externally-threaded male member II4 like, in all respects, the male member I4 of each end section III, except that the threads thereof are opposite in hand, having at its base a similar stop shoulder or abutment I20. In the other end of major portion 23 of side section II is provided an internally-threaded female socket I I5 like, in all respects, female socket I5 of end-section I except that the threads thereof are opposite in hand, with the end edge I22 circumambient of its mouth 2I providing a stop shoulder or abutment similar to 22. It will thus be seen that the male members I4, I4 of end sections I8, I0, and male members I I4, 4 of side sections II, II, are respectively mateable with female sockets H5, H of the side sections and the female sockets I5, l5 of the end sections. I

It is to be understood that features of the present invention may characterize certain chain shackle structures consisting only of end sections and side sections without the employment of stud structure I2. However, in the preferred embodiment, stud structure, such as that illustrated in the drawings, is emploed, and reference thereto will best illustrate the lay-out of the link sections prior to their threaded assembly and their manipulation relative to each other during threaded assembly. Thus, it will be noted from Figs. 2 and 3 that each side section II preferably has mounted to the side of major per- .4 tion 23 and extending normal thereto, a stud lug 24, preferably provided with an enlarged externally-threaded head 25 at its outer end connected to the side link section by a reduced unthreaded shank 26. An internally-threaded connecting sleeve 21 is threadably engaged on one of the externally-threaded enlarged stud lug heads 25 and preferably is of a length appreciably shorter than the combined lengths of the two externallythreaded enlarged heads 25, 25, as shown in Fig. 1, when properly aligned in opposed relation as shown in Fig. 4. It will readily be seen that by providing the external male threads of the enlarged stud lug heads 25, 25 of the same hand, the mating internally-threaded sleeve 21 may be run partially 01f of one onto the end of the other when in opposed relation. On each stud lug shank 25 is loosely mounted an internallythreaded lock nut 28 adapted to be threadably engaged on the externally-threaded enlarged head 25 and juxtaposed to an adjacent end of the connecting sleeve 21 when medially arranged as indicated in Fig. 1 to be jammed thereagainst for the purpose of locking. It will be noted from Fig. 1 that the connecting sleeve 27 and the lock nuts 28, 28 jammed against opposed ends thereof normally substantially cover the external threads of the enlarged heads 25, 25 for protective purposes.

In order to assemble a stud link chain shackle of the structure shown in Figs. 1, 2 and 3, a pair of semi-elliptical end sections III, II! will be laid out, preferably on a flat surface, with a male member I4 opposed to and spaced appreciably from a female socket I5 of the other in substantial alignment. A pair of side link sections II, II will then be interposed therebetween with the enlarged head 25 of the stud lug 24 of one carrying connecting sleeve 21 run back thereon, all as illustrated in Fig. 2. The male members II4, I I4 of the side link sections I I, I I and the female sockets H5, H5 thereof naturally will be respectively substantially aligned with the female sockets I 5, I5 and the male members I4, I4 of the end sections. The opposed end sections II], III are then pushed toward each other to engage all of the male members into all of the female sockets. Then the side sections II, II are rotated about their axes in opposite directions so as to draw up the threads of the male members into the threads of the female members. Thus, as indicated in Fig. 3, with the male members I4, I4 of the end sections I0, I0 being provided with left-handed threads mateable in the female sockets H5, H5 of side sections II, I I, and with the male members II4, I I4 of the latter provided with right-handed threads mateable with the female sockets I5, I5 of the end sections, rotation of the side sections in opposite directions, for example, clockwise for the upper side section and counter-clockwise for the lower side section as viewed in Fig. 3, the male members will be threaded into the female sockets to draw the end sections toward each other.

Eventually such threaded engagement of parts will bring the abutment shoulders 28, 29 of the end sections Ill, II and the abutment shoulders I20, I20 of the side sections II, II respectively tightly up against the abutment edges I22, I22 of the side sections and 22, 22 of the end sections. If abutment shoulders and edges are carefully located axially of the sections so that as the abutment shoulders and edges are so drawn up tightly together, the stud lugs 24, 24 will be brpught to alignment in opposed relaf tiontas; indicated; in..Eigs-. 1.: and 4,.so that; con?- necting; sleeve. 21 may be run partially off. of the: externally-threaded. enlarged. stud lug; head- 25. carrying; it onto; outenport-ion of the; other enlarged stud. lug: head and; whenmedially receive lock: nuts; as; Fig.'. 1.. S'ubstantialz coverage: of: the external threads. of" the: enlarged: heads 25,. 255 of: stud:

lugs. 21;, 2.4 by connecting sleeve. 21 and. lock nuts. 28,. 28 protects. them. from" damage; by handling equipment, such; as Wildcats; and by contact" with. other chain links: during. handling or' storage: in chain lockers; Thus,pdisassembly of'parts. is readily: permitted; for. separating sec.- tions. of chain whendesired; or. to permit replacement of worn. parts. of links. of: the: present invention.

Asmi'ghtLlienoted fromi Fig; 2; .buiLas best, seen in-F'igs. 5, G andi 7,:aaportionaof themalethread l6 T at the tip 29 of each malev member lit or; H .4' isremoved; or cut away... is clearly indicated in Fig. 7: by. the. dot-hatched: areatii; Similarly, a portion of the-end of the female thread H: at the mouth 2.4. of female socket [5 or H5 is removed asindicatedbyrthe dot-liat'ched area- 3| of Fig. 6.. Such: thread portion removal facilitates initiah int'erengagemerit since the end 32. of male: threadi It. will.

boreat the-socket-mouth. The 8. feature.

permits appreciable socketing prior to. rotational. thread' engage-mentwithout necessity of careful orientation asmight be necessary: with less threadremoval-as inthe case of Figs. 5; 6 and7;

However, thelesser extent of thread removal illustrated in Figs. 5', 6 and 7 is sufficient for the purposes of chain shackles of the stud link types, such as those illustrated in Figs; 1 to 4, inclusive due-tothe fact that lay-out of the link parts asproposed in Fig. 2 includes juxtaposition inopposition of the stud lugsZ-d, 2J5 which automatically dictates the relative orientation:

which permits the end 32 of male thread It to -slide past the end 3-3 of female thread il of any; mateable' pair.

equipped with such transverse stud structure, the. exaggerated thread removal of Fig. 8 may be preferred since; in such-case, structuresof link parts do not so readily provide guiding orientation.

ItWiH be understood from Fig; 9 that-the basic parts of; the stud link chain shackleof Figs. 1 to 4"; inclusive, maybeutilized to advantage-with additional elements for constructioncf links of" different dimensions. For example, with the pair of semi-elliptical end sections til, Itand the' pair of stud lug-equipped side sections H, H; additional side section inserts 3%, 3 1 and 35, m'ay' be employed, each arranged between mateabl'e ends of end sections and stud lugequipped side sections. In such case, it is to be. understood" that onepair of such insert sec tions'. 3 3; 34' is similar toside sections ll, (with, of course, the omission of stud lugs- 24;

Such removed. portion- Ii, however, the invention is to; be practicedwith chain shackles not" 24),.but. with: the threads of. the male members. and: female; sockets thereof. being opposite; in. hand,. while; they other pairof insert. side sections 35, 35 may be. substantial duplicates of those side sections (except for omissionof. the

stud lugs). with. the threads of their male. members. 'andifemale' sockets: of like hand. ThuS the" male; member; [4 of: each; end section H]- may. carry a left-handed: threadiwiththe; thread: of the. female: socketrof-side insert: 34 opposed there;- to. being mateabl'e; therewith. and. with its; male member It; also. provided with. a. left-handed thread; In. such.cas.e,; the. female socket of each; side section II will have: an. internal thread matieabl'e; with the. threads of; the male membersrofeither: the end section; Ill. or the: insert section. 3.4. interposed. therebetween. With the male member [Id of side: section. Hi provided with aright-handed thread,.the internalthread. of its receptive socket ininsert. section 35'will be. mateable. therewith, and" the. external thread of the: male. member He of the latter willalso be right-handed formating with the internallythreaded socket l5 of the other end section. In order-to assemble the parts of an extended link structure, such as that proposed in Fig. 9, it. willbe understoodithat. the insert sections may firstbe threadably mounted to any of the mating. juxtaposed threaded ends of the basic link sections. and the resultant composite parts, or section units comp-rising assembled elements then finally assembled as in the manner previously described It is to be noted that the insert sections may be varied in shape and length as may be desired, or morethereof, may-be em-- ployed' to constructlinks of still longer dimensions'.

Attention is called to thefact. that in laying out the basic partsof alink of. the present invention, such. as proposed in Fig; 2, they are arranged in symmetrical. order. with all the mouths of the female sockets. opening in one direction and all of themale members extending in the opposite direction toward the latter entirely around the link in the. same direction so as to simplify'for. one unfamiliar with such link structure the assembly operations. It is obvious to. anyone that male membersimust be opposed; to: femalev sockets and. when: this is accomplished; theyare automatically mateable, thereby eliminating trial and error procedure, which. maybe. extremely important under trying, conditions, particularly in the-field under-combat. conditions: Further, it will; be noted that. the; end sections: are duplicates of each other: and that the; side;

sections are duplicates of each other, thereby minimizing cost of'productiom Also, the. structural characteristics of. the; parts; of such chain: shackles readily makepossible. practice of a variety of types of manufacturing procedure. For example, although. the. sockets-and. threads read;- ily can .be formed by suitable .heavyduty; drilling and cutting machines; itis possible, particularly it has been found also to be advantageous to form each male member of an O. D. of about two-thirds or more of the O. D. of the link structure on which it is formed.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description are efficiently attained and, since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It'is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

-l. A chain shackle comprising, in combination; a pair of integral, rigid, C-shaped end sections each having a female threaded socket in one'end thereof and a male threaded member extending from the other end thereof; and a pair of integral, rigid, side link sections each having a male threaded member extending from one end thereof and a female threaded socket in the other end thereof; each of said side sections being interposable between opposed female and male ends of said end sections with the threads of its male member and female socket respectively complementary with the threads of the opposed female and male ends of said end sections, the threads of said end section male members being like and the threads of said side section male members being like but opposite in hand to the former, the threads at the tip of each male memher and in the mouth of each, female socket bemg each terminated in an axially extending portion located in a predetermined radial position to dictate similar orientation of opposed like parts and to permit sliding reception of each male member into its complementary female socket, thereby facilitating simultaneous initial interengagement of all four threaded pairs, whereby said shackle may be assembled and disassembled solely by simultaneous rotation in opposite directions of said side sections.

2. The chain shackle as defined in claim 1, characterized by the provision of said male and female members with substantially large dimension and steep pitch threads each extending no more than about two full turns.

3. The chain shackle as defined in claim 1 characterized by the provision of a pair of opposable stud lug each extending from one side of each of said side sections and adapted to be held together to form a cross stud, said mating male and female threads having their engaging entry ends oriented relative to each other to cause said stud lugs to be aligned for securement against relative rotation when the four sections are drawn up relatively tightly together to form a stud link.

4. The stud link as defined in claim 3 characterized by the provision of externally-threaded enlarged cylindrical heads on the outer ends of said lugs to be juxtaposed with threads thereof being of the same hand whereby the thread of one may form a continuation of the thread of the other when axially aligned, said lugs having reduced-section unthreaded shanks inward of said heads, an internally threaded sleeve threadably receptive of both of said lug heads to connect them together with portions of the male threads exposed at both ends of said sleeve, and a pair of lock nuts with one located on each of said unthreaded shanks adapted to engage and substantially cover the otherwise exposed portion of the male thread adjacent thereto.

5. A chain shackle of the stud link type comprising, in combination; a pair of substantially like, rigid, c-shaped end sections each having an internally-threaded socket in one end thereof and an externally-threaded male member extending from the other end thereof substantially parallel to said socket with the male threads like and the female threads being like but opposite in hand to the male threads; a pair of substantially like, rigid, side link sections each having a male member extending from one end thereof and carrying a male thread complementary to the female thread of either of said sockets and threadably engaged in one of said sockets, each of said side link sections having a socket in the other end thereof provided with a female thread complementary to the male thread of either of said end section male members and threadably receiving one of the latter; each of the tips of each male thread at the end of each male member and of each female thread in the mouth of each socket being terminated in a foreshortened end portion located in a predetermined radial position which dictates similar orientation of opposed like sections and permits limited socketing without relative rotation for facilitating initial sliding reception of each male member into its complementary female socket and simultaneous initial inter-engagement of all four threaded pairs of male members and female sockets, whereby said shackle sections may be assembled together solely by simultaneous rotation in opposite directions of said side link sections; and a pair of opposed stud lu s each extending from one side of each of said side sections toward the other side section and temporarily held to the stud lug of the latter to prevent unintended reverse rotation of said side link sections and attendant undesired disassembly of shackle sections.

6. The stud link as defined in claim 5 characterized by the provision of externally-threaded enlarged cylindrical heads on the outer juxtaposed lug ends with threads thereof being of the same hand whereby the thread of one forms a continuation of the thread of the other, said lugs having reduced-section unthreaded shanks inward of said heads, said internally-threaded sleeve exposin portions of the male threads at both ends thereof, and a pair of lock nuts engaging and substantially covering the otherwise exposed portions of the male thread adjacent the ends of said sleeve.

7. A chain shackle of the stud link type comprising, in combination; a pair of opposed, substantially like, similarly square-threaded, rigid, C-shaped end sections each having a male threaded end and a female threaded socket end with the female threads opposite in hand to the male threads; a pair of substantially like, similarly square-threaded, rigid, side link sections each having a male threaded end complementary to the female threaded socket of either of said end sections and a female threaded socket end complementary to the male threaded end of the.

other of said end sections, the mouth of each of said sockets and the core of each of said male ends at its base being complementally flared and run out, the threads of the sockets and male members terminating short respectively of the mouths and tips thereof each in an axially-extending portion located in a predetermined radial position to dictate similar orientation of opposed like parts and to permit limited sliding reception of each male member into its complementary female socket to facilitate initial interengagement; stop structure at the socket mouths and male end bases for mutual abutment to stop relative rotation in threading them home located axially with respect to the threads as to cause opposed points on the sides of said side sections to be oriented directly opposite each other with the mating threads drawn up relatively tightly; a pair of aligned opposed stud lugs each fixed to one side section at its mentioned point and REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,454,335 Prendergast May 8, 1923 2,347,088 Dock Apr. 18, 1944 

